Leaning out under WOT
Sounds like the pump isn't getting the voltage it needs. It would make sense that since the car is under alot less load in 1st and 2nd that WOT would be ok and having problems in 3rd/4th. Either way, try digging and finding the thread about the poor soul who's pump lost voltage.
Yes...I am that poor soul...and no..I haven't been able to fix the problem..I can tell you right now..don't waste your money on the fuel pump relay,CHANGED IT..DIDN'T WORK..UGH I have the service owners manual..that gave me the order of operation for the fuel system. My next two things to look at are the fuel pump resistor and possibly the MAF..but Chris from AMS said the MAF was fine..they discovered that the fuel pump voltage doesn't kick up. My car is modded exactly like yours...I just wish I knew if the O2 sensor some how controlled a signal that changed fuel pump voltage..be sure to check the fuel pump resistor..now that this has happen to someone else I don't feel crazy...
Next thing I would look at is the map sensor... X prefers the map sensor under WOT, if for any reason the voltage output of the map sensor is clipped, it will calculate a much lower load and you won't have the fuel you need, Don't think this will cause 15:1 under WOT though, fpr line certainly will though.
Did you and the OP both check to make sure you did not pop the line off the fuel pressure regulator? That would be the simplest explanation.
Next thing I would look at is the map sensor... X prefers the map sensor under WOT, if for any reason the voltage output of the map sensor is clipped, it will calculate a much lower load and you won't have the fuel you need, Don't think this will cause 15:1 under WOT though, fpr line certainly will though.
Next thing I would look at is the map sensor... X prefers the map sensor under WOT, if for any reason the voltage output of the map sensor is clipped, it will calculate a much lower load and you won't have the fuel you need, Don't think this will cause 15:1 under WOT though, fpr line certainly will though.
on my x im test pipe, catback, open filter and upper ic pipe makin 317 and my injectors are maxed out up top. im 24psi tappered to 18psi. dont know if this helps
Last edited by 04gsr; Apr 21, 2009 at 05:08 PM.
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Yes...I am that poor soul...and no..I haven't been able to fix the problem..I can tell you right now..don't waste your money on the fuel pump relay,CHANGED IT..DIDN'T WORK..UGH I have the service owners manual..that gave me the order of operation for the fuel system. My next two things to look at are the fuel pump resistor and possibly the MAF..but Chris from AMS said the MAF was fine..they discovered that the fuel pump voltage doesn't kick up. My car is modded exactly like yours...I just wish I knew if the O2 sensor some how controlled a signal that changed fuel pump voltage..be sure to check the fuel pump resistor..now that this has happen to someone else I don't feel crazy...
How do you go about doing this? I don't have a service manual, so I'm not sure where the fuel relays are.
The filling up of the gas tank was not a joke. Under half a tank, the fuel pickup starts to have a hard time picking up fuel which is fixed by adding more fuel to the tank.
Many road racers have experienced this first hand.
We have also experienced this on the dyno with multiple cars.
Many road racers have experienced this first hand.
We have also experienced this on the dyno with multiple cars.
The filling up of the gas tank was not a joke. Under half a tank, the fuel pickup starts to have a hard time picking up fuel which is fixed by adding more fuel to the tank.
Many road racers have experienced this first hand.
We have also experienced this on the dyno with multiple cars.
Many road racers have experienced this first hand.
We have also experienced this on the dyno with multiple cars.
At first I thought you were joking til I read someones thread today about fuel cuts at 5500 rpms. I have this same exact problem if I have less the a half tank of gas.
Would the walbro pump be a fix to this hypothetical issue?
Also, how do you know the injectors are maxed out? What size stock injectors do we have?
Last edited by Excalibur; Apr 22, 2009 at 05:54 PM.
Can you provide a link to this? I would like to read up on it. I'm running stage 2 and would like to know what's wrong if I find I have the same problem.
Would the walbro pump be a fix to this hypothetical issue?
Also, how do you know the injectors are maxed out? What size stock injectors do we have?
Would the walbro pump be a fix to this hypothetical issue?
Also, how do you know the injectors are maxed out? What size stock injectors do we have?
https://www.evolutionm.net/forums/ev...-happened.html
Well I purchased a Walbro 255 fuel pump. I hope this fixes the problem. I'll post results this weekend.
Can you provide a link to this? I would like to read up on it. I'm running stage 2 and would like to know what's wrong if I find I have the same problem.
Would the walbro pump be a fix to this hypothetical issue?
Also, how do you know the injectors are maxed out? What size stock injectors do we have?
Would the walbro pump be a fix to this hypothetical issue?
Also, how do you know the injectors are maxed out? What size stock injectors do we have?